new platform util (#5791)

src/alf/util/platform.ts

@@ -1,25 +1,62 @@
-import {isAndroid, isIOS, isNative, isWeb} from 'platform/detection'
+import {Platform} from 'react-native'
 
+import {isAndroid, isIOS, isNative, isWeb} from '#/platform/detection'
+
+/**
+ * Identity function on web. Returns nothing on other platforms.
+ *
+ * Note: Platform splitting does not tree-shake away the other platforms,
+ * so don't do stuff like e.g. rely on platform-specific imports. Use
+ * platform-split files instead.
+ */
 export function web(value: any) {
   if (isWeb) {
     return value
   }
 }
 
+/**
+ * Identity function on iOS. Returns nothing on other platforms.
+ *
+ * Note: Platform splitting does not tree-shake away the other platforms,
+ * so don't do stuff like e.g. rely on platform-specific imports. Use
+ * platform-split files instead.
+ */
 export function ios(value: any) {
   if (isIOS) {
     return value
   }
 }
 
+/**
+ * Identity function on Android. Returns nothing on other platforms..
+ *
+ * Note: Platform splitting does not tree-shake away the other platforms,
+ * so don't do stuff like e.g. rely on platform-specific imports. Use
+ * platform-split files instead.
+ */
 export function android(value: any) {
   if (isAndroid) {
     return value
   }
 }
 
+/**
+ * Identity function on iOS and Android. Returns nothing on web.
+ *
+ * Note: Platform splitting does not tree-shake away the other platforms,
+ * so don't do stuff like e.g. rely on platform-specific imports. Use
+ * platform-split files instead.
+ */
 export function native(value: any) {
   if (isNative) {
     return value
   }
 }
+
+/**
+ * Note: Platform splitting does not tree-shake away the other platforms,
+ * so don't do stuff like e.g. rely on platform-specific imports. Use
+ * platform-split files instead.
+ */
+export const platform = Platform.select